Shock absorber



FIG. 1 shows a front view of a shock absorber showing my new design;

FIG. 2 shows a rear view thereof;

FIG. 3 shows a top view thereof;

FIG. 4 shows a bottom view thereof;

FIG. 5 shows a left side view thereof;

FIG. 6 shows a right side view thereof; and,

FIG. 7 shows a perspective view thereof. 

The ornamental design for a shock absorber, as shown and described. 